Published: May 24, 2010 12:31 AM EDT
Updated: May 24, 2010 12:31 AM EDT

CAPE CANAVERAL, Fla. (AP) - After a week together in space, the shuttle and station crews shared some final laughs Sunday as they bid one another farewell and sealed the hatches just a few hours ahead of Atlantis' departure.

Atlantis was set to undock late Sunday morning and, with its six astronauts, head for home. Landing, though, isn't until Wednesday.

"Take care," the International Space Station's skipper, Oleg Kotov, told his shuttle visitors.

"We'll see you all on the surface of planet Earth again soon," said shuttle commander Kenneth Ham.

The two commanding officers shook hands twice and laughed heartily, then embraced. Their crewmates - representing the United States, Russia and Japan - followed suit.
      
Earlier in the morning, Ham told reporters the two crews had fun. He said all 12 space fliers bonded through hard work and worked as a single team.
      
The space station is bigger, thanks to Atlantis and its crewmen. They're leaving behind a new Russian compartment packed with supplies, as well as six freshly charged batteries and other equipment that was hooked up during a series of spacewalks.
      
Its total mass exceeds 816,000 pounds, and it's 98 percent complete in terms of living space.
      
"This place is now a palace. It's huge, and I've had great fun exploring it," said shuttle astronaut Piers Sellers. "we're seeing station in pretty much its final form, and it's really magnificent."
      
Two shuttle missions remain to wrap up NASA's share of construction. Discovery is scheduled to fly in September, followed by Endeavour in November.

As it currently stands, once Atlantis lands, it will never fly in space again.

NASA and some politicians are pushing hard for another mission, however, so Atlantis can haul up a final load of supplies in June 2011. The White House - which wants NASA concentrated on getting astronauts to asteroids and Mars in the coming decades - would need to approve any extra flights.
      
Already, NASA is going through the list of museums interested in Atlantis and Endeavour. Discovery is promised to the Smithsonian Institution.